The problem asks us to subtract two polynomials: $(7m^3 + 5m^2 - m + 2.3) - (-2m^3 + 9m + 3.3)$.

1. Problem Description

The problem asks us to subtract two polynomials: $(7m^3 + 5m^2 - m + 2.3) - (-2m^3 + 9m + 3.3)$.

2. Solution Steps

We need to subtract the second polynomial from the first. This involves distributing the negative sign to each term in the second polynomial and then combining like terms.

$(7m^3 + 5m^2 - m + 2.3) - (-2m^3 + 9m + 3.3)$

$= 7m^3 + 5m^2 - m + 2.3 + 2m^3 - 9m - 3.3$

Now, we combine like terms:

Terms with $m^3$: $7m^3 + 2m^3 = 9m^3$

Terms with $m^2$: $5m^2$

Terms with $m$: $-m - 9m = -10m$

Constant terms: $2.3 - 3.3 = -1$

So, the result is $9m^3 + 5m^2 - 10m - 1$.

3. Final Answer

$9m^3 + 5m^2 - 10m - 1$